Air-borne Particulate Matter and Its Characteristics in the Indoor/Outdoor Environment of the Most Populated City of India
JAMSON MASIH, Sachin Gupta, Lorraine Tellis, Chemistry Department, Wilson College
Abstract Number: 355
Working Group: Health-Related Aerosols
Abstract
Present study focus on the characterization of the fine particulate matter in indoor and outdoor air. PM2.5 samples were collected from Nov 2022 to April 2023 indoor and outdoor air of domestic home of Mumbai, India. Twenty four hour >PM2.5, PM1.0 to PM2.5, PM0.50 to PM1.0, PM 0.25 to PM0.50, and < PM0.25 were collected on 25-mm PTFE filter paper using Sioutas Impactor with SKC Leland Legacy Sample Pump operated at 9 L/min. The sampled filters were digested in 6–8 ml HNO3 and kept on a hot plate at the temperature of 40–60 °C for 90 min, the solution was diluted with a known volume and analyzed on ICP-AES. The concentation of PM2.5 was found be higher in outdoor 102.22ug/m3 than indoors 115.61 ug/m3. The total contribution of analyzed metals in PM 2.5 was 60 to 70% in indoors and outdoors. The concentration trends of trace metals in indoor and outdoor was in the order Al>Fe>Zn>Pb>Cu>Mn>Cr>Ni. Al, Fe and Zn was found to be dominant and higher in indoor and outdoor air. The probable reason of being the higher Zn concentration in indoor and outdoor was due to automobiles such as lubricating oils and tires, while Al and Fe may arise from ressuspended dust. The sources of analyzed metals are house dust and anthropogenic activities indoors and another from infiltration from outdoors. Particulate matter were higher in the outdoor environment and below the permissible limit in indoor environment during the study period as recommended by Central Pollution Control Board and WHO. SEM-EDAX results showed flaky like appearance with the average size of 100 nm to 250 nm collected on a PTFE filter paper. Chemical composition of PM 2.5 and PM < 0.25 micron showed elements Cu, Al, Ca, K, Si, S and other metal ions. High concentration of Al and Si can be attributed to the presence of Aluminosilicates.The results of the present study are of practical importance in identifying sources and processes that control levels of fine particulate matter in a reparable size range. Further, the elemental constituents of reparable size range particulate matter are of public health interest, as it determines human susceptibility to pollution processes.